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As of Windows 10 Anniversary Update, there was the inclusion of an awesome new tool that allowed users to have their very own Bash terminal on Windows without needing to run a Linux image in a hypervisor. This new tool was called the Windows Subsystem for Linux, which shipped with it’s own copy of a Canonical sanctioned variant of Ubuntu 14.04. The differences between it and a normal Ubuntu installation to any experienced Linux user would probably identify a couple of things that stuck out as being different. First item up is that the Kernel details listed Microsoft, second item up is that a lot of the linux utilities would either not return the right information, or just outright fail. Ansible for example is one such tool that I use and didn’t work under this new subsystem because semiphores were not entirely supported yet.

What Microsoft did was essentially create their own kernel in what they call a “pico-process”, which is essentially a proxy between Linux kernel calls to the Windows kernel’s implementations (or using bridges for things that didn’t quite match up. This environment, even with the terminal window on the screen, doesn’t use up any system resources – until a command is executed. It’s pretty cool and as of this blog post, entirely negated the use VirtualBox for me to run Fedora locally to get a fully functional Bash terminal.

As of Windows 10 Creators Update, the proxy-kernel has been updated and pretty much supports everything I could imagine wanting to run now, without any issues. Along with the kernel updates was an update to the Ubuntu image that you could use, which is now Ubuntu 16.04. The one thing I don’t like about the whole thing is this lock-in to using Ubuntu, when I’m pretty much a fanboy of the RedHat ecosystem – from RHEL, CentOS, Amazon Linux, and to Fedora. But now there’s a way to not only use this subsystem with a different Linux distribution, you can use it with multiple distributions.

Getting Updated Ubuntu Image – Suggested way

This will literally nuke everything you have in the existing Ubuntu environment. Be sure to backup everything you care about NOW, before running the following command.

Close any existing Bash terminal windows you may have open

Execute the following two commands

C:\> lxrun /uninstall /full /y
C:\> lxrun /install

Ensure that you enter in the username and password of choice after the last command that you’ll use going forward with that environment.

Getting Updated Ubuntu Image – Easy way

This will keep everything you have in place and do an in-place upgrade, but Microsoft doesn’t suggest it. It would be a good idea to backup things anyways even though you should theoretically be safe here.

$ sudo do-release-upgrade

I guess if you’re fine with Ubuntu, then you’re done. Have fun, see you again in another year when I decide to blog again.

If you’re not fine with Ubuntu like I am, then we have some more work to do…

Another Distribution – Downloading

The README for the GitHub project we just cloned shows the following images and tags are available as of August 18th:

This will only download a Docker repository image of a distribution you’re interested in. It does not install it, that’s another step. You can run this multiple times for the distributions you’re interested in, if you choose.

Install Python3 in your Windows environment (not inside the Linux subsystem) and include it in your PATH.

Open a command or PowerShell Prompt

Execute the following command

git clone https://github.com/RoliSoft/WSL-Distribution-Switcher.git

Move into the git directory

Rename the hook_postinstall_all.sample.sh file to hook_postinstall_all.sh

Execute the following command using the appropriate tags defined above

python get-prebuilt.py [docker_image_identifier]:[image_version]

Another Distribution – Installing

Now we’re going to switch into the distribution we want and just downloaded.

Close any existing Bash terminal windows you may have open

Execute the following command

python install.py [docker_image_identifier]:[image_version]

Open the Bash terminal by launching the “Bash on Ubuntu on Windows” link in the start menu again

Execute the following command:

dnf --version

Another Distribution – Switching

You can repeat the download and install steps multiple times, for each distribution you’re interested in. The last install ran makes the subsystem of that distribution, but each install performed on the machine stays, and it makes a note of each installation performed. Which makes this next step much awesome and so wow.

$ python switch.py
usage: ./switch.py image[:tag]
The following distributions are currently installed:
- amazonlinux:latest
- fedora:latest
- ubuntu:trusty
To switch back to the default distribution, specify ubuntu:trusty as the argument.

The downside is that you aren’t able to have multiple distributions active at the same time, but switching like this is still pretty awesome.

Well, now that I’ve shared that information, I’m going to go clear up 80gb of disk space by removing VirtualBox and it’s assorted images.

For more information, see the blog post from Microsoft here and the README of the project you just blindly cloned to your machine and arbitrarily ran commands from because a blog post referenced it.

I’ve been working on a side project at home the last few days to snipe hard to find restaurant reservations and came across a weird issue I’ve never experienced before while using the .NET framework.

The API I’m calling to find these opportunities returns a DateTime value in the format “2016-11-21T23:00:00-05:00” which could be read as “November 21st, 2016 11:00pm (EST)”. Now while we’ve read the “-05:00” as the timezone offset which equates to the Eastern Time Zone, it appears the .NET framework in the DateTime.Parse() method, takes that as a hint to adjust the value relative to the local timezone instead to “November 22nd, 2016 4:00am”. Can’t imagine any restaurant that is hard to get is open at 4am in the local time.

While on my laptop (using EST) it was working just fine, deploying this to say… an Azure instance (using UTC) introduces just enough frustration to want to kick puppies and pop a small child’s balloon in passing.

I’ve seen it for years in the intellisense popup in Visual Studio without ever looking at it, and now I know why it’s there. The lifesaving DateTimeOffset type works just like the DateTime type, but when fed the value I needed parsed instead sees the timezone value as an offset (thus the type’s name), not an adjustment hint.

Hopefully you see this before you do anything horrible to a young canine or child. For the record, doing either is mean. Asshole.

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April 2, 2015 by wholroyd·Comments Off on Agent-less method to enumerate certificates on a remote machine

Ever needed to enumerate certificates installed on a remote machine using just C# and .NET without having to use an agent? It was a problem I’ve had a couple of times now and was able to figure out without the help of MSDN or StackOverflow. I discovered the X509Store class has the power to solve this problem for us as it utilizes the C++ CertOpenStore functionality underneath, but it’s not documented anywhere. As a result, you can use some of the same functionality as the underlying library at the C# level, just by simply doing this…

[gist https://gist.github.com/wholroyd/b7026197c485c6085c60]

It’s evidently the second time I’ve had to do this type of lookup. Luckily I remembered to post the answer back to my own StackOverflow question years ago.

One of the projects I’ve spent the past month working on is a system called Foundation that will eventually become the company’s one stop shop for automation and workflow management. It’ll keep track of everything from services to environments, and the resources they are using underneath in our private cloud and public cloud provider.

In the process of learning Code First Entity Framework for the first time (all previous provides were Data First), I came across an interesting event that you could use to prepare entities before they are committed to the database. For example, you have some entity properties that need to be checked at last minute and possibly changed. You could do the following without having to layer in an abstract DbContextBase between your own context implementation and DbContext that overrides SaveChanges() to perform the same work before calling the same method off the base class…Continue reading

These same instructions can be applied to Visual Studio 2013 as well by substituting the ‘11.0’ value for ‘12.0’. For those of you using Visual Studio Express 2013 for Web, the same instructions while substituting the ‘VisualStudio’ value for ‘WDExpress’ will work.

With whatever version you are using, if you don’t want to open the Registry Editor, you can also enable it using PowerShell and the appropriate registry string like so…

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I thought I might talk about my pre-blogging days of trying to learn PowerShell when I was trying to avoid learning the VBScript language (I don’t care much for the synatic qualities of the language).

I personally love the PowerShell language as I’m familiar with both C# and PHP, and (at least to me) it looks like a bastard child of the two. The creation and intialization of objects or variables are done the same way as in PHP and has the same method and property accessors that you’d come to recognize in C#. It took me about an hour to pick up the basics of the language, but I just needed to learn how to create classes so I could start causing some damage.

Unfortunately one of the lacking items in PowerShell, even after version 2 is the lack of native classes. The strength of the .NET framework has always been behind the PowerShell language, but it’s never been directly accessible unless you’ve built cmdlets that allow you such power, so your reliance on custom classes have required you to compile them using Visual Studio. Until such time comes around, there are at least a couple of workarounds.

I had pinged a few people around Microsoft to see if it might be possible after reading this blog entry regarding the CTP3 release of PowerShell v2 if the method in how one would dynamically compile C# code into an console application could be used in other ways. It evidently wasn’t quite clear from the original post, so James Brundage from the PowerShell team posted this blog entry showing how you can use the same technique to compile C# based classes on the fly in a script. Pretty neat!

If you’re not a blogger, but know PowerShell pretty well, let me know about any hidden or not-so-known tricks in PowerShell that you know of and I can make an entry for you. Credit will be given!